Add "Redirect USB device" option in console viewer. Initialize and
embed UsbDeviceWidget object from SpiceClientGtk into a dialog to
let user choose available USB devices for redirection.
Throw an error message if USB connection failed.
Auto-redirection is enable by default.
There is race between creating usbredir channel and calling
has_usb_redirection() when initializing spice session like
happening on virt-viwer. So adding a new signal handler
on_details_menu_virtual_manager_activate() to recheck the
status of usbredir channel, set "Redirect USB device" option
sensitive if it is availiable.
88f2d1abe0